I want to brew two 6 gal. lagers. A pils and a schwarzbier. I made up 6 L. of DME starter and pitched 2 nicely puffy smacks of WY 2124 Boh Lager around noon today. Yeast and wort at 60 F. Split it up between 6 one gal. jugs and shook the hell out of them. They are in the temp controlled fridge at 60* ±2* (caps loose).
When can I expect to brew the beers? When should I start reducing temp to 48-50 F ?
as I understand it you should pitch when they are at or near high krausen so sometime around midnight tonight.
I don’t know that I would pitch 3 liters of starter wort into a 6 gallon batch of beer.
Personally, I’d crash them in the fridge when they hit high krausen (if I happened to be around at the time), let the yeast settle out of suspension, decant the liquid, and pitch just the yeast.
If I was asleep or at work when they hit high krausen, I’d just crash them in the fridge as soon thereafter as I was able.
I had 2 lager starters for a Helles, and put them in the fridge at high Krausen. Guess what, when I opened the fridge they were still going strong! I didn’t want 4 liters of unhopped weaker wort in my Helles, so I put them back out warm till they finished, crashed, and chilled the Helles wort to 39F for 2 days. Pitched the crashed yeast and all seemed to work well.
Yeah, I’ve been letting my starters ferment to completion and then crashing and decanting for years, and it has always worked very, very well for me. Crashing at high krausen is something I just started experimenting with.
Another question: What should high krausen look like on a lager starter at 60*? Also, how long might it last?
It should work great for ale yeast, my experience with a lager stain the fridge was not so good. Maybe a chest freezer at 30F would be better.
I do not crash shaken starters. However, then again, I never go beyond a liter for a 5 to 6-gallon batch of ale or lager. Growth is exponential, not linear. The difference between a 1L starter and a 2L starter is one replication period.
I pitched the yeast to the starter 30 hrs ago and it doesn’t look like it’s near high krausen yet. What would likely be the time of a replication period for a lager yeast at 60*F ?
No, the replication period is the amount of time that it takes for a yeast culture to double cell count-wise. Under ideal conditions, the cell count doubles every 90 minutes after the lag phase has been exited. Doubling time increases as temperature decreases.
Sixty degrees Fahrenheit is way too cold for a starter. That’s why your starters are taking forever to reach high krausen. Starters should be incubated at 25C/77F (i.e., room temperature), regardless of yeast species (ale and lager yeast strains are different yeast species). The goal of a starter is to increase yeast biomass, not make beer.
Thanks, I very much appreciate your input. So, I should get those jugs of starter out of the fridge and let them warm up to 72+ to reach high krausen. Then cool to 48-50 to pitch in the main wort. Correct?
I would try dropping the temperature down to just above freezing from 77F. The yeast cells should sediment if the temperature drops quickly enough and the culture is a Frohberg strain such as W-34/70 (Saaz-type strains may not settle due to their improved cold tolerance). The culture should be left at this temperature until you are ready to decant the supernatant (the clear liquid that lies above the solids). The supernatant should be decanted immediately upon removing the culture from the refrigerator; otherwise, the yeast cells will go back into suspension.
Most brewing yeast cultures are NewFlo flocculation strains (FLO is the name for the family of genes that control flocculation). NewFlo flocculation is inhibited by the presence mannose, glucose, maltose, sucrose, and maltotriose. Hence, most brewing strains will not remain sedimented until all of these sugars have been consumed or have reached a genetically encoded level.
All of the sugars encountered in brewing are multiples of CH2O (carbon hydrate or carbohydrate). Mannose and glucose are monosaccharides that belong to a family of sugars known as hexoses because they contain six carbon atoms. All of the hexoses have the same chemical formula; namely, C6H12O6.
Maltose and sucrose are disaccharides that consist of two hexoses bound by what is known as a glycosidic bond. We lose one water molecule for every glycosidic bond; hence, the chemical formula for maltose and sucrose is C12H22O11, not C12H24O12. Maltose consists of two glucose molecules bound by a glycosidic bond. Sucrose consists of one glucose molecule and one fructose molecule bound by a glycosidic bond.
Maltrotriose belongs to a class of sugars known as trisaccharides. Trisaccharides consist of three monosaccharide molecules bound by two glycosidic bonds. In the case of maltotriose, it is made up of three glucose molecules bound by two glycosidic bounds. The chemical formula for maltotriose is C18H32O16.
By the way, there are non-NewFlo brewing strains, but they are outnumbered by the NewFlo strains by a large margin. The non-NewFlo strains belong to the Flo1 family. These strains are inhibited by the presence of mannose. As Martin covered in his recent article, flocculation is dependent on calcium (Ca2+) ions. That’s because the substance on the surface of yeast cells that causes them to stick together is a lectin-like protein that is encoded to recognize sugars. Lectins require Ca2+ for binding activity.
I don’t want to sound snarky but that’s what the silly yeast calculators call for. In fact they want 4 L !
Well…here’s what I did.
I took the 6 jugs of starter out of the fridge and let them warm up overnight. In the morning they looked like they had reached high krausen earlier but were still cooking along. I did a taste test and the beer tasted quite good, albeit un-hopped.
Since it’s against my religion to throw out perfectly good beer, I brewed up my worts as planned, swirled the jugs and pitched the whole shebang. 
I’ll report back on how they turn out.
I am interested to hear your results. I think one of the big reasons that so many brewers are hesitant to pitch the full volume of a rather large starter is because for a fully-attenuated/finished/flocculated stirplate starter there is a large risk for oxidation in the starter beer. I have to believe that the risk for oxidation is minimal for a shaken-not-stirred starter pitched at high krausen, because the yeast are still working and there is not a continuous introduction of O2.
You said that the starter beer tasted good, so right there that tells me that you are in good shape. Keep us posted!
I pitched the starters to the main worts at 8:00 last night. Checked about 8:00 this morning and both have big krausen going (the schwarz is threatening to crawl out of the airlock). Fridge is at 49*, the therm strips on the carboys say 52-54*.
I am ecstatic! In my first attempt at lagers, two days before Christmas, I used not near enough old, poor dry lager yeast. Lag time was 5 days and it took 5-1/2 weeks to ferment. I’m just getting to drink some this week. This forum has been a huge help.
I should add that, last night, the starters appeared to be past high krausen but still working actively.
I have used this method, after a few long discussion with Mark, and have been totally won over.
I am not sure I will go back. The ease, cost, and results are noting short of amazing!
In my humble opinion, the foulness found in a stirred starter is more the result of shear stress on the yeast cells than continuous introduction of O2. That ugliness without an increase in performance is the reason why I quit using my stir plate and went back to my old starter method.
I developed my starter method during a period of time when my understanding of yeast was nowhere near what it is today. Much like the discovery of penicillin, this method came about via serendipity. I started out making one quart starters in a 48oz glass Ocean Spray juice container. I went to make a starter and noticed that the container had sustained a sizable chip between uses. I had a 1-gallon jug that I used for making mead, so it used it. While no one would believe it today, I was seriously into strength training in my twenties and early thirties. Shaking the dickens out of a starter was just the result of being very strong. I noticed a huge increase in performance, so I stuck with the method long enough to understand why it worked.
I only offered the method to the forum because so many new brewers are led to believe that they cannot make healthy pitchable starters without making a sizable investment in an Erlenmeyer flask, a stir plate, and a stir bar. I knew that that claim was not true because I propagated yeast cultures from slant for a very long time before I started to use a stir plate. In reality, all that matters is adequate O2 and carbon coupled with good yeast transfer technique. As I mentioned earlier, most brewing strains exhibit NewFlo flocculation; therefore, they do not need help remaining in suspension.
Duly reporting progress as requested: 36 hours after pitching starters to main worts.
HOLY COW! I should have rigged blow off tubes. For lagers at 49* F ? Whoda thunk it.
Now I’ve got a mess to clean up in the fridge.
Exactly my bit*h! And since my brew fridge can accommodate two 6.5 gal. carboys, I like to brew two batches on the same day. That means that I would need two heavy duty stir plates and two 5 L flasks w/stir bars. A $400 cost that I could better use on other stuff.
Plus, that would mean eating the cost of 5-8 L of spent starter wort/beer that I would have to rack off and throw out.